Water tube boiler



WATER TUBE BOILER Filed June 11, 1928 5 Sheets-Sheet 1 Dec. 29, 1931.

H. E. YARROW WATER TUBE BOILER Filed June 11, 1928 5 Sheets-Sheet 2 Dec. 29, 1931. H. E. YARROW 1,839,074

WATER TUBE BOILER Filed June 11, 1928 5 Sheets-Sheet 5 .EZUiZZOM fldf'aa arrow Dec. 29, 1931. H E YAR W 1,839,074

WATER TUBE BOILER Filed June 11, 1928 5 Sheets-Sheet 4 Dec. 29,1931. H E. YARROW 1,839,074

- WATER TUBE BOILER Filed June 11, 1928 5 Sheets-Sheet 5 fizaerefor Mr ZpZLE, ,Q'IVOZO Patented Dec. 29, 1931 UNITED TATES HA OLD EDGAR mmqw, or SGOTSTOUN, SCOTLAND wAr'nn'rUBE BOILER.

Application filed June 11, 1928, Serial N'o."284,402, and -in Great Britain August n, 1927.

This invention relates to water tube boilers of the Yarrowtype comprisingan elevated steam and water drum connected by steam generating tubes withwater drums extending parallel with the steam drum along the front andrear of the furnace. I I

One object of the present invention is to 7 provide means for effectively screening the floor of the boiler casing from excessive ra- 1e diation from the combustion space. Another i .with F igshl and 3 showinga further modiiications object is to provide a capacious combustion chamber having aportionwhich is substantially rectangular in cross section surmounted by another portion of substantially trian- 1a 'ular section as in the ordinal Yarrow t eboiler. Another object is to enclose the combustion chamberco npletely by steam generating waterltubes so as to screen effectively. the entire cas1ng,s1desas wellas floor, from t QXCGSSLVG heat.

According to the present inventionthe floor ofthe boiler casing is screened from excessive radiation by. providing a pairof additional water drums which are-situateda 7 considerable distanoe below the ordinary or main water drums of theboiler and extend either parallel therewith orytransversely thereto and are connected by water tubes with each other and with either the steam 1w drum or with the main water drums, or with a, low level water drums areprovided, two arranged parallel with and substantially directly below the. main water drums, and two arranged transversely in front and rear respectively of the combustion space, but only one of these pairs of additional water drums need be interconnected by means of water tubes," these interconnected drums being preferably at somewhat different levels to promote circulation of the water.

For convenience it will be assumedin the subsequent description that the boiler has only two main water drums, at each side of the combustion space, but it is to be understood that there may be more than two such steam superheater, reheater, or other heating accessories. F F i V In the accompanying drawings Figs. "l and 2; are vertical sections ,in planes at righ t angles to each other of a Yarrow type boiler. embodying the invention; Figs. 3' and 4 are corresponding views of a modified construction and Fig. 5 is a view corresponding jorimainwater drums of a Yarrow boiler connected with the steam drum A respective- .ly by banks C, C of steam generating tubes.

Two additional water drums D, D areprovided parallel with and directly belowqthe water drums -B ,l3 respectively. The drums B, D are connected by rows of verticalgen- {crating tubes F and the drums B Diare similarly, connected by rows of verticalgeneratingtubes F To ensure adequate circulation in the tubes F, F? downcomers. H may be provided between thedrums B, D and similarly down- PATENT OFFICE comers Hibetween the drums B D Al-- ternatively, downcomers J, J? ma be arranged toconnect the water space 0 the 'sat- .urated steam drum A with the lower water drums D, D? as shown in Figs. 3 and 4. Or both sets of downcomers H, H and J, J 2 may be provided as shown in Fig. 5.

As shown in Figs. and 2 the lower water drums D, Diare at slightly diiierent levels and inthis case the auxiliary transverse drums E, E arranged respectively at either side of the boiler,.are situated parallel with each other at a level intermediate between the lower water drums D,"D

The auxiliary transverse drums :E, E are connected with the water space of the saturated steam drum A by rows of tubes G formingside'screens protecting the side Walls of .95

theboiler casing/from excessive heat, and

enclosing the combustion space the two sides.

The tubes G 65 alternatively the tubes Q main water drums all substantially at the 1 F or are preferably arranged'iii groups leaving interspaces L between adjacent groups to accommodate burners suitable for firing the boiler by burning within the combustion space pulverized fuel, oil fuel, blast furnace gas or other suitable form of fuel.

The two lower water drums D, D being at difierent levels, may be connected by one or more rows of inclined tubes K which form a screen between the combustion space and the floor of the boiler setting.

In the modified construction of Figs. 3 and 4 the only material difierence is that the lower water drums D, D are arranged parallel with eachother on the same horizontal plane while the auxiliary transverse drums E, E are arranged parallel with each other but on different levels, one above and the other below the water drums D, D The drums E, E may be connected by one or more rows of tubes I enclosing the bottom of the combus' tion space and screening it from the floor of the furnace casing, and as the drums E, E are at dii'i'erent levels, the gradient of the tubes I ensures the maintenance of the water circulation in the system of water tubes of which they form part. Further, as previously described, the drums D, I) are connected by downcomers J, J not with the main water drums B, B but with the water space of the steam drum A. In other respects the two constructions are substantially identical, and the same reference characters are applied to corresponding parts in the several figures.

As shown in Figs. 1 and 3 of the drawings the'waste gases from the combustion space pass to uptakes on the two sides of the steam drum A, but obviously a bafiie may be provided on one side, e. g. between the steam drum A'and water drum B as shown in Fig. 5, so as to constrain the waste gases to pass to a single uptake on one side of the steam drum A. In this case the water drum omitted when it is not desired to enclose the front and rear of the combustion space by water tubes.

Adequate circulation in the screening tubes is secured by making each set part of a closed water circuit, and in the case of the floor screen the tubes are given a pronounced inclination to the horizontal. I

Having thus described the nature of the said invention and the best means I know of carrying the same into practical efl'ect, I claim 1. A Yarrow type water tube boiler comprising a steam drum, two main water drums, one at each side of the combustion space, a pair of additional water drums situated within the boiler setting at a considerable distance below the main water drums, downcomer water tubes and upriser water tubes connecting the said additional pair of water drums with the main water drums, a second additional pair of water drums arranged substantially at right angles to the first-mentioned pair of additional water drums, the individual drums of one of said pairs of ad ditional water drums being at different levels, water tubes connecting the said second pair of additional water drums with the steam drum, and inclined water tubes connecting the individual drums of the pair of additional water drums which are at different levels.

2. A Yarrow type water tube boiler comprising a steam drum, two main water drums, one at each side of the combustion space, a pair of additional water drums situated within the boiler setting at a considerable distance below the main water drums, downcomer water tubes and upriser water tubes connecting the said additional pair of water drums with the main water drums, a second additional pair of water drums arranged substantially at right angles to the first-mentioned pair of additional water drums, water tubes connecting the said second pair of additional water drums with the steam drum, and inclined water tubes connecting the individual drums of the said first pair of additional water drums, said individual drums being at different levels.

In testimony whereof I have signed my name to this specification.

HAROLD EDGAR YARROIV. 

